Covered elastic thread or the like



' Jan. 3, 1928.

L. B. CHISHOLM COVERED ELASTIC THREAD OR THE LIKE Filed Jan 5, 1927 Patented Jan. 3, 1928.

LESTER B. CHISHOLM, OF 'STONEHAM, MASSACHUSETTS covnnnn ELASTIC THREAD OR THE LIKE.

Application filed January 3, 1927. Serial No. 158,622.

The invention relates to an improvement in covered elastic threads or the like useful in the making of elastic fabrics, and the object of the invention is to overcome certain 6 defects inherent in these threads as now commonly employed.

Where an elastic thread is employed in the making of an lil$di fabric difficulty arises in case one of the elastic threads is broken,

as for example when the fabric is being machine-sewed the needle may sever some one of the elastic threads. The effect is when one of the elastic threads is broken for the severed ends of the thread to draw or run into the fabric which effect is aggravated because the thread usually lies within the fabric under some tension. After the ends of the broken thread have run or contracted into the fabric the thread will lie substantially inert, no longer functioning as an elastic. Not only this, but the inelastic thread covering with which the elastic thread or core is provided, no longer being supported along the point of the cut will tend to unwind and become loose, giving the fabric an unsightly appearance at the point where the break or out has occurred. The object of the invention, as said before, is to overcome this difficulty, and the way in which it is overcome can best be seen and understood in the light of the drawings in which Figure 1 is a short section or piece of elastic core thread.

Fig. 2 shows this same thread twisted.

Fig. 3 shows the core thread provided with its inelastic thread covering in accordance with the principles of the invention as will hereinafter be explained, and

Fig. 4 is a section of the elastic core thread and inelastic thread covering, more or less diagrammatic, for illustrating the principles inherent in the invention.

Referring to the drawings 1 represents the elastic core thread. This thread is of a type commonly employed in elastic fabrics and is usually square in cross section.

This thread is made to have a slip-resisting surfacing 2. For obtaining such surfacing the thread has applied to it some substance that will make the surface of the thread of a slip-resisting character. This may be, and preferably is, accomplished by running the thread through a bath of rubher cement, preferably leaving the cement unvulcanized on the surface of the thread,

thereby tacky.

After the surfacing of the thread it is twisted, this being effected while the thread is stretched or taut and the twist is preferably continued to a point where, when the thread is allowed to relax, its outer surface will present the appearance of a multiplicity of spiral coils. In other words, the elastic core is rather hard twisted, although the twist is not carried so far that it will in any way interfere with the functioning of the core as an elastic medium, but will rather tend to increase it.

The twisted elastic core thread held taut is then provided with an inelastic thread covering 3. This covering is wound around the core thread with coils running spirally making the surface more or less in a direction reverse to the direction in which the core thread is twisted. After the winding of the thread covering, which may by any suitable covered core thread is allowed to relax and assume its normal shape when the coils of the covering will be brought together contacting wth one another which defines the normal length of the structure, the core thread then being maintained under some tension within the covering.

hen a covered thread is thus made, if the core thread be cut or broken at any point the tendency will be for it to untwist. The direction of its untwisting will be in the direction that the coils of the thread covering are wound, and accordingly the core thread, tending to untwist, will frictionally grip the coils of the thread covering and will thereby tend to further wind the covering at the point where the core thread is cut or tends to untwist. This has the resulting effect of tightening the thread covering onto the core thread, venting the core thread from drawing back into the frabric and at the same time winding up the thread covering at the point of rupture so that in the fabric the thread covering will present no unsightly appearance as any looseness in the thread covering at the point of rupture is taken up.

Instead of using a. single twisted core thread for forming the elastic core, more than one thread, as for example two or three elastic threads twisted together, ma be employed and precisely the same principle pre vai with even increased eflect.

Having thus fully described my invention,

I claim and desire to secure by Letters-Patent of the United States 2- 1. An article of manufacture comprising a twisted elastic core having a slip-resisting surfacing and a non-elastic thread covering wound spirally around said-twisted core in a direction reverse to the direction of twist in said core.

2. An article of manufacture comprising a twisted elastic core and an inelastic thread covering with coils wound spirally, around said core in 'a direction reverse to the direc tionrthat said core is twisted whereby said core will tend to untwist inthe same direction that said thread covering is wound and by its frictional engagement with the coils of said covering will tend to further wind the covering.

3. An article of manufacture comprising a twisted elastic core having a slip-resisting surfacing and an inelastic thread covering with coils wound spirally around said core in a direction reverse to the direction that said core is twisted whereby said core will tend to untwist in the same direction that said thread covering is wound and by its frictional engagement with the coils of said covering will tend to further ing.

4. An article of manufacture comprising a twisted elastic'core, a slip-resisting surfacing material or cement applied to the surface of said core, and an inelastic thread covering with coils wound spirally around. said core in a direction reverse tothe direction that said core is twisted whereby said core will tend to untwist in the same direction that said thread covering is wound and by its frictional enagement with the coils of said covering will tend to the covering.

I LESTER B. CHISHOLM.

wind the coverfurther wind 40 

